Circuit board



FIG. 1 is a front, lower, left perspective view of a circuit board showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a right view thereof;

FIG. 5 is a left view thereof;

FIG. 6 is a top view thereof; and

FIG. 7 is a bottom view thereof.

The broken lines in the drawings illustrate unclaimed features of the circuit board and form no part of the claimed design. 

CLAIM The ornamental design for a circuit board, as shown and described. 